Stud terminal rail bond



Patented Nov. 12, 1940 UNITED STATES PATENT OFFICE STUD TERMINAL RAIL BOND Application January 29, 1937, Serial No. 123,073

3 Claims.

This invention relates to rail bonds of the stud terminal type and to their installation.

The accompanying drawin'gr illustrates a speciiic example of the invention, in which:

Figure 1 is a partial sectioned top view of the exemplary bond.

Figure 2 is a side view.

Figure 3 is a side view of a. suitable tool for use in the installation of the bond.

Figure 4 is a top view of the tool.

'I'he illustrated bond includes a relatively short conductor strand I having terminals at either end, these terminals in each instance having a head 2 to which the strand connects and a stud 3 right angularly extending from this head. The bond is of the type intended to be installed to the sides of the heads of the rails to be bonded, the recesses in which the studs 3 fit being formed at appropriate locations for thispurpose.

According to the invention, a tapereddepression I is formed in the head 2 of each terminal so as to extend inwardly from the side opposite the stud 3 toward the latter but so as to terminate within the head at a location spaced from its junction with the stud. The stud and head are integral and solid throughout except for the der pression 4 formed in the latter.

This depression 4 is axially aligned with the stud 3 and has a blunt bottom so that the metal from the head between this bottom and the stud may be forged into the latter by a suitable bluntnosed tool so as to effect expansion of the stud in the rail recess. 'Ihe tool illustrated for thispurpose consists of a solid steel head 5 equipped with a suitable handle 6 and having a tapered portion 1, the extreme end of which is relatively blunt. Preferably, the taper of this portion is between 20 and 30 degrees, experience having proven that this is most suited to provide for properly holding the terminal against the side of the rail while at the same time permitting a portion of the metal of the terminal head to be forged into the solid metal stud.

Actual penetration of the stud 3 is not normally desired, but it is to be noted that in instances where the terminal may have been pulled from the rail and reinstalled several times, actual penetration of this stud is permissible to eiect further expansion. However, the primary idea is to forge a part of the metal of the head centrall7 into the stud so as to effect the latters expansion without destroying its solid connection. It is for this reason that the terminal under discussion possesses greater shear strength. It is unnecessary to make the stud 3 longer than the rail recess is deep, although this may be done n uesired.

The installed terminal is clearly distinguished from others in that a portion of the metal of its head is forged centrally into the solid stud so as to increase the volume of metal in the recess over that normally iilling the same. It is possible to determine whether a terminal is installed in this manner, because the outside of the head provides visual evidence that it has been forged inwardly. It can also be ascertained by proper cross-sectioning, polishing, and etching, whereby to condition it for microscopic examination, the crystalline strain providing clear evidence of the forging. It is to be understood that such forging will normally be done cold.

I claim:

1. A rail bond terminal having a stud adapted to ilt a rail recess and a head from which said stud extends and inwhich a tapered depression is formed extending inwardly from its side opposite said stud toward the latter but terminating within said head at a location spaced from said stud, r

the latter and said head being integral and solid excepting for said depression in said head.

2. A rail bond terminal having a stud adapted to nt a rail recess and a head from which said stud extends and in which a tapered depression is formed extending inwardly from its side opposite said stud toward the latter but terminating within said head at a location spaced from said stud, the latter and said head being integral and solid excepting for said depression in said head, said depression being axially aligned with said stud and having a blunt bottom so that the metal from said head between said bottom and said stud may be forged into the latter by a suitable hngt-nosed tool so as to effect expansion of said s u 3. A rail bond terminal having a stud adapted to iit a rail recess and a head from which said stud extends and in which a depression is formed extending inwardly from its side opposite said stud toward the latter but terminating within said heat; at a location spaced from said stud, the latter and said head being integral and solid except for said depression in said head, and there being sufficient material between the bottom of said depression and said stud for forging into the latter to materially increase its volume without its penetration by a tool or the like, whereby said stud may be increased in volume while retaining its solidarity completely throughout.

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